In order to avoid an obstacle (a fallen object, an accident or the like) found while running on an expressway or a surface street, a vehicle may show a behavior such as harsh braking or abrupt steering. Therefore, a traffic jam or a traffic accident may occur due to a disturbed traffic flow caused by the harsh braking or abrupt steering. Road administrators constantly monitor roads by using a patrol vehicle or a monitoring camera. Road administrators notify general-purpose vehicles of impediment information by incidental facilities on roads such as an information board when an impediment is found.
PTL 1 also discloses a method and a device, which may determine, by a vehicle behavior measuring sensor mounted on a general-purpose vehicle, whether a behavior of the vehicle is abnormal travel. If the vehicle behavior is determined to be abnormal, the method and the device may transmit the behavior of the vehicle that has been determined as abnormal to a server, determine presence or absence of an obstacle and make notifications.